Cycas javana

Cycas javana is a cycad of the island of Java, in Indonesia, where it grows in closed evergreen forest inland, often near streams in the mountains. Described by Miquel in 1842 as a mere variety, Cycas circinalis var. javana, and then forgotten for more than a century, this member of the genus Cycas was raised to species rank only in 1996. It is recognised by its very glossy leaves and its narrow megasporophylls, regularly toothed with sharp spines. Much of its habitat has been cleared, and The World List of Cycads gives it as Critically Endangered on the IUCN Red List.

Key facts about Cycas javana

  • Accepted name: Cycas javana (Miq.) de Laub. ex D.Yue Wang (1996), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted directly
  • Former names and synonyms: Cycas circinalis var. javana Miq. (1842), the basionym; plants long referred to Cycas rumphii
  • Family: Cycadaceae, order Cycadales
  • Common names: no English name attested; no vernacular name recorded in the sources consulted
  • Natural range: Indonesia, Java (West, Central and East Java) and the neighbouring island of Kangean
  • IUCN status: Critically Endangered (CR, criteria A2ace+4ace) according to The World List of Cycads; year of the assessment not verified
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: closed evergreen forest inland, often near streams in mountain areas; persists in disturbed areas
  • Habit and adult size: trunk 2 to 4 m tall and 15 to 20 cm across; leaves up to 205 cm long
  • In the UK, US and Australia: no garden record found
  • Toxicity: no data for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas javana

According to Lindström, Hill and Stanberg (2009), Cycas javana is distinguished by its seeds, which lack a spongy layer, and by the narrow blade of its megasporophylls (the fertile leaves of female plants), regularly toothed with many sharp spines. Its large, flat leaves are a very glossy green, faintly bluish as they expand. In their key to the Indonesian species, it is the one combining a narrow megasporophyll blade (less than 35 mm wide) with broad leaflets (more than 10 mm). Description after Lindström and colleagues (2009):

  • Trunk: upright, 2 to 4 m tall and 15 to 20 cm across at the narrowest point.
  • Leaves: up to 205 cm long, dark to mid green, highly glossy, faintly bluish as they expand, flat, with about 146 leaflets; brown or orange-brown down shed as the leaf opens; ending in a spine up to 6 mm long or a pair of leaflets; petiole 30 to 60 cm, hairless, spiny over 40 to 90% of its length.
  • Median leaflets: 24 to 37 cm long and 10 to 15 mm wide, inserted at about 50°, much paler below, narrowed to 2.5 to 6 mm at the base; margins slightly to moderately recurved; tip acute; midrib raised on both sides.
  • Cataphylls (the scale leaves protecting the crown): linear, soft, covered in rich orange-brown hairs.
  • Male cones: ovoid, orange or brown; apical spine of the microsporophylls prominent and sharply upturned.
  • Megasporophylls: 22 to 36 cm long, with persistent brown down, carrying 2 to 8 hairless ovules; blade lanceolate, 60 to 100 mm by 11 to 30 mm, regularly toothed, with 12 to 30 sharp lateral spines 5 to 20 mm long; apical spine distinct, 10 to 65 mm long.
  • Seeds: not seen by these authors; lacking a spongy layer according to their key and comments.

De Laubenfels and Adema (1998), working from the few specimens then known, gave somewhat different figures: trunks up to 6 m, leaves 120 to 140 cm (probably longer, they noted, judging from leaf fragments), male cones 30 to 70 cm long, and orange seeds 45 to 60 mm long. Their concept of the species also included plants from southern Sumatra and Krakatoa, which Lindström and colleagues do not retain.

Hybrids

No hybrid is documented. Lindström and colleagues only note that plants from the Tanimbar Islands, provisionally referred to Cycas scratchleyana, might reflect intergradation with Cycas javana, or belong to another taxon; the question has not been studied.

Possible confusion

  • Cycas rumphii, into which Miquel merged it: a mainly coastal cycad of eastern Indonesia, whose seeds have a spongy layer that lets them float, and whose megasporophylls are almost spineless;
  • Cycas edentata, a cycad of the coasts of western Indonesia: megasporophylls with indistinct lateral spines, spongy seeds; de Laubenfels and Adema (1998) add that sterile material of the two is very similar;
  • Cycas scratchleyana, from New Guinea and the Moluccas, in the same group: a much broader megasporophyll blade (more than 35 mm), with 28 to 40 teeth;
  • Cycas montana, described from the mountains of Flores: narrow leaflets, less than 10 mm wide;
  • Cycas circinalis, from south-western India, of which Miquel made it a variety: a quite distinct species, which does not grow in Indonesia.

Taxonomy

Cycas javana is a name accepted by The World List of Cycads and by GBIF; POWO could not be consulted directly. The Dutch botanist Friedrich Anton Wilhelm Miquel described it in 1842, in his Monographia Cycadearum (p. 28, plates I and II), as Cycas circinalis var. javana, from a specimen collected in Java by Carl Ludwig Blume (Blume 1089, holotype at Leiden, on two sheets). De Candolle still listed it in 1868, but Miquel later merged it into Cycas rumphii, and the name was left aside until 1996.

David de Laubenfels raised it to species rank in the collective work Cycads in China, published in 1996 under the editorship of F.X. Wang and H.B. Liang (p. 65). The combination is attributed there to de Laubenfels but appears in a chapter by D.Y. Wang without any explicit statement of his contribution; according to The World List of Cycads, the Code of nomenclature then requires the form “de Laub. ex D.Yue Wang”. Lindström, Hill and Stanberg (2009) consider the treatment of the species by de Laubenfels and Adema (1998) “essentially correct”, although those authors misapplied several other Indonesian names. They place it in subsection Cycas of section Cycas, with Cycas scratchleyana and Cycas apoa, a group defined by seeds without a spongy layer. For the reader, this means that Javan plants labelled Cycas rumphii or Cycas circinalis in older works may belong to this species.

Etymology and history

The epithet is formed from the name of the island of Java, with the Latin suffix -ana indicating a connection: it refers to the species’ occurrence on Java and its first collection there (Lindström et al. 2009; Haynes 2022).

The old collections kept at Leiden and Bogor, made between 1889 and 1954 by Koorders, Backer and other botanists of the colonial period, cover the whole of Java, from the Pelabuhan Ratu area in the west to Mount Watangan, near Puger, in the east, as well as Kangean Island. Reference plants collected in 1999 near the village of Cibaraja, beside a stream in West Java, are grown at Nong Nooch Tropical Botanical Garden in Thailand, and the megasporophyll illustrated by Lindström and colleagues came from a plant cultivated at the Cibodas Botanic Garden in Java.

Common names

No common name is recorded for this species, in English, French or Indonesian, in the sources consulted.

In the wild

Cycas javana is apparently endemic to Java and the neighbouring island of Kangean, to the north-east (Lindström et al. 2009); The World List of Cycads records it in the provinces of West, Central and East Java. It grows in closed evergreen forest inland, often near streams in mountain areas, and persists in disturbed areas. On Kangean it was collected at low altitude (22 m); in West Java, at about 500 m. De Laubenfels and Adema (1998) described its habitat as the understorey of lowland rainforest and extended its range to southern Sumatra and Krakatoa, a broader concept that the 2009 revision does not follow.

Its pollinator, phenology and seed dispersers are not documented; the authors of the 2009 revision had not seen the seeds themselves. GBIF holds only ten records under this name (consulted on 21 October 2026), mostly herbarium specimens.

Conservation status and regulation

According to The World List of Cycads, Cycas javana is listed as Critically Endangered (CR) by the IUCN, under criteria A2ace+4ace: a severe past and projected reduction of the population, linked to the decline of its habitat and to exploitation. Two assessments are referenced on Crossref, one by Ken Hill published in version 2010-3 of the Red List and one by Anders Lindström published in version 2023-1; which of them gave this category could not be checked, since the Red List could not be consulted and the IUCN data relayed by GBIF show no category for the species (consulted on 21 October 2026).

In 2009 Lindström and colleagues noted that much of the original habitat had been cleared for agriculture, but that healthy populations remained in some higher areas; they then recommended the status Near Threatened, the official category at the time being Data Deficient (Donaldson 2003). The Asian cycad scale, Aulacaspis yasumatsui, is widespread on Java (see Pests and diseases).

Like every species in the genus except Cycas beddomei, Cycas javana is listed in CITES Appendix II, through the listing of the family Cycadaceae, included since 4 February 1977. The listing carries annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen, seedlings or tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are exempt, whereas international trade in the plants themselves requires an export permit. Australia, the United Kingdom and the United States apply CITES through their own national legislation; in the European Union the species is in Annex B of Regulation (EC) No 338/97, whose annexes in force are set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+, the official CITES database, names the species, with Indonesia as the range state, and confirms this status (searches of 3 and 12 October 2026). This general information does not replace the official texts: check the rules in force before buying or exchanging plants, ask the seller for proof of origin and prefer plants raised from cultivated seed.

Growing Cycas javana

In short: Cycas javana is grown in a few tropical collections, but no growing advice specific to the species has been published, and no grower’s report was found. Its habitat, humid evergreen forest in the tropics, points to a plant needing warmth, humidity and some shelter; this is a deduction from its habitat, not a growing result.

Outdoor and in-ground cultivation

Plants are grown in tropical botanic gardens: at Nong Nooch in Thailand (reference plants from West Java) and at Cibodas in Java, and the species was once represented at the Bogor Botanic Garden (specimen Stolk 149) (Lindström et al. 2009). Only frost-free tropical and near-tropical climates can be considered; no planting in the open ground is documented in the United Kingdom, the United States or Australia.

Container cultivation

In temperate climates it would need a warm, humid glasshouse; no container growing report has been found. Searches of the French forum Fous de palmiers and the Italian forum Tropicamente found no growing report on this species (almost all the results for “javana” concerned a palm, Pinanga javana), and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on it.

In cultivation in the UK, US and Australia

No British, American or Australian garden declares Cycas javana in BGCI PlantSearch; the only two declarations are from the Fairy Lake Botanical Garden in Shenzhen, China, and the Hortus Botanicus in Amsterdam (search of 21 October 2026). A BGCI entry shows that a garden has declared the species, not that the plant is alive today. No accession was found in the online catalogue of Montgomery Botanical Center (Florida), and the species is absent from the inventory of cycads in British, American and Australian gardens compiled for this site (19 October 2026). No report from an English-speaking grower could be read; PalmTalk and Dave’s Garden could not be consulted.

Propagation

The plant is dioecious: a male and a female plant are needed to obtain seed. No germination data specific to the species have been published. Seeds are exempt from CITES under annotation #4; ask for seed from cultivated plants.

Pests and diseases

No disease specific to the species is documented. The Asian cycad scale, Aulacaspis yasumatsui, widespread on Java and Bali, is the main threat reported: it long ago wiped out the once extensive Cycas collection of the Bogor Botanic Garden, and the wasp that preys on it elsewhere seems to be absent from these islands (Lindström et al. 2009). The same scale has killed many cultivated cycads in the United States, according to the studies they cite.

Cold hardiness

No cold-tolerance data exist for Cycas javana. Java has a tropical climate, and nothing allows us to say that the plant tolerates frost.

Mediterranean experience

No growing result has been published in Europe, in the open ground or in a pot, and no dated frost event concerns the species.

United Kingdom, United States and Australia

No cold reading or dated growing report was found, either on forums or from botanic gardens. No USDA zone can be given. In the UK and in most of the United States and Australia outside the tropics, keep it under heated glass.

Toxicity and precautions

No toxicity analysis specific to Cycas javana has been found. The risk is, however, well documented in the genus: Cycas tissues, and the seeds above all, contain cycasin, which is converted during digestion into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA. The ASPCA lists the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses. Until proven otherwise, treat the plant as poisonous: keep seeds and leaves out of reach of children and pets, and wear gloves to clean the seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No use specific to this species is documented in the sources consulted.

Frequently asked questions

What does javana mean?

“Of Java”: the species grows on that Indonesian island, where it was first collected.

Is it a variety of Cycas circinalis?

No. Miquel described it as such in 1842, but it is a distinct species, raised to that rank in 1996; the true Cycas circinalis grows in India.

Where does Cycas javana grow?

On Java and the neighbouring island of Kangean, in evergreen forest inland, often near streams in the mountains.

How can it be told from Cycas rumphii?

By its seeds, which lack a spongy layer, and its narrow megasporophylls toothed with many spines; Cycas rumphii is mainly a coastal plant with floating seeds.

Is it endangered?

Yes. The World List of Cycads gives it as Critically Endangered on the IUCN Red List; much of its forest has been cleared, and the cycad scale is widespread on Java.

Is it hardy?

Almost certainly not. No cold data exist; it is a plant of tropical forest.

Is it poisonous?

It must be assumed so. No analysis exists for the species, but all the cycads studied contain serious toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Miquel, F.A.W. (1842). Monographia Cycadearum: 28, t. 1, fig. t, u; t. 2, fig. E1. [Basionym Cycas circinalis var. javana; not consulted, cited after Lindström et al. (2009) and The World List of Cycads.]
  • Wang, D.Y. (1996). In: Wang, F.X. & Liang, H.B. (eds), Cycads in China: 65. [Publication of the combination Cycas javana; not consulted, chapter title not recorded, reference after The World List of Cycads.]
  • Lindström, A.J., Hill, K.D. & Stanberg, L.C. (2009). The genus Cycas (Cycadaceae) in Indonesia. Telopea 12(3): 385–418. doi:10.7751/telopea20095826 [Description, key, history, range, habitat, status (pp. 395–396), cycad scale on Java; full text consulted.]
  • Laubenfels, D.J. de & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [Treatment of the species pp. 380–381 (description, range including southern Sumatra and Krakatoa, habitat), judged essentially correct by Lindström et al. (2009); full text consulted.]
  • Hill, K.D. (2010). Cycas javana. The IUCN Red List of Threatened Species 2010-3: e.T42093A10629129. doi:10.2305/IUCN.UK.2010-3.RLTS.T42093A10629129.en [Red List assessment; reference checked on Crossref, Red List page not consulted (access blocked).]
  • Lindström, A. (2023). Cycas javana. The IUCN Red List of Threatened Species 2023-1: e.T42093A68903080. doi:10.2305/IUCN.UK.2023-1.RLTS.T42093A68903080.en [Red List assessment; reference checked on Crossref, Red List page not consulted (access blocked); category not verified at source.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Source of the etymologies given by The World List of Cycads; not consulted directly.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. doi:10.5281/zenodo.21958524 [Reference checklist; consulted directly.]